Digital Spot Imaging: From 1 Different Sources
(DSI) the production of static images using an *image intensifier, usually during a fluoroscopic examination. The images can be stored digitally (see digitization) and either transferred to photographic film or viewed on a TV monitor.
A radiological technique for detecting osteoporosis (see BONE, DISORDERS OF) in which a beam of X-rays is directed at the bone-area under investigation – normally the spine and hip – and the CALCIUM density measured. If the calcium content is low, preventive treatment can be started to reduce the likelihood of fractures occurring.... quantitative digital radiography
See MRI.... magnetic resonance imaging
See MRI.... magnetic resonance imaging(mri)
See angiography.... digital subtraction angiography
See barium X-ray examinations.... intestinal imaging
A blue-black pigmented spot found on the lower back and buttocks at birth. The spots are a type of naevus and are caused by a concentration of melanocytes (pigmentproducing cells). Mongolian blue spots are commonly found in black or Asian children, and they usually disappear by the age of 3–4 years.... mongolian blue spot
A general term for a small lump, mark, or inflamed area on the skin.... spot
See barium X-ray examinations.... stomach imaging
Techniques for visualizing the kidneys, usually performed for diagnosis. Ultrasound scanning can be used to identify kidney enlargement, a cyst or tumour, and the site of any blockage. Conventional X-rays show the outline of the kidneys and most kidney stones. Intravenous urography shows the internal anatomy of the kidney and ureters. Angiography is used to image blood circulation through the kidneys. CT scanning and MRI provide detailed cross-sectional images and can show abscesses or tumours. Two types of radionuclide scanning are used for the kidney: DMSA and DTPA scanning. DMSA is a substance given by intravenous injection that binds to cells in the kidney tubule, giving a single, static picture of the kidneys. DTPA, also given intravenously, is filtered in the kidneys and passes out in the urine. Pictures taken at intervals record its passage through the urinary tract and show kidney function. ... kidney imaging
see Doppler ultrasound.... colour flow ultrasound imaging
any technique that produces an image in the form of a section through the body with the structures cut across. The main techniques are *ultrasonography, *computerized tomography, *magnetic resonance imaging, and some *nuclear medicine techniques (see positron emission tomography; SPECT scanning). If a series of thin-section images is stacked they can be ‘cut’ through to show other planes or allow reconstruction of three-dimensional images.... cross-sectional imaging
a variant of *diffusion weighted imaging in which both the direction and the amount of diffusion of water molecules in a tissue are coded in the image. This MRI technique can be valuable in linear structures, such as nerves and muscle fibres. In the brain the major tracts and their communications can be studied with this technique (see tractography).... diffusion tensor imaging
a method of creating images by *magnetic resonance imaging that relies on the amount of available space that individual water molecules have to move in, which depends on the local microstructure. Pathological tissues generally are less organized, with more space for diffusion and a higher signal.... diffusion weighted imaging
adj. 1. (in anatomy) relating to a digit. 2. (in radiology) relating to or utilizing *digitization.... digital
see hearing aid.... digital hearing aid
an image made up of *pixels. Each pixel has numbers (digits) to describe its position and shade on the *grey scale. The more shades available, described by the number of computer bits required to store the shade of grey, the more accurately the image represents the original tissue contrast. An 8-bit computer image shows 28 (256) possible shades of grey, close to the maximum the human eye can differentiate. 12-bit (4096 levels of grey) images are of much higher quality and take up more memory. They can be manipulated more easily by computer using image enhancement techniques. Compare analogue image.... digital image
(DR) an alternative to film radiography, by acquiring X-ray images from a large number of individual X-ray detectors on a matrix in a digital format directly. This contrasts with *computerized radiography, in which an *analogue image is taken and then put into a reader to be converted into a *digital image. The technique allows the storage of images and their subsequent retrieval, manipulation, and interpretation using computers (see PACS).... digital radiography
see Doppler ultrasound.... duplex imaging
(fMRI) a type of *magnetic resonance imaging that measures the increased hemodynamic response seen with neural activity in the brain or spinal cord. fMRI has allowed major advances in brain mapping (i.e. matching sections of the brain with particular behaviours, thoughts, or emotions).... functional magnetic resonance imaging
see co-registration.... fusion imaging
n. (in radiology) the production of images of organs or tissues by a range of techniques. These images are used by physicians in diagnosis and in monitoring the effects of treatment. They can also be used to guide *interventional radiology techniques. See also computerized tomography; magnetic resonance imaging; ultrasonography.... imaging
an emerging area of imaging that exploits recent developments of molecular and cell biology to create new markers. Most molecular imaging uses versions of these markers labelled with radioactive isotopes, which – after administration – are localized in the body and can be detected using such techniques as *positron emission tomography, *SPECT scanning, *magnetic resonance imaging, and optical imaging.... molecular imaging
the trading name of the *Health and Social Care Information Centre (HSCIC) since 1 August 2016. It is the national provider of information, data, and IT systems for commissioners, analysts, and clinicians for the National Health Service (England). It also runs the *NHS Choices website.... nhs digital
a radiological technique that enhances visualization of blood vessels (see angiography). A digitized image is taken before the contrast medium (a ‘mask’) is injected, and this is subtracted by computer from the images taken after contrast injection. Only the blood vessels remain on the image. The technique enables blood-vessel anatomy and blood supply to an organ to be demonstrated more clearly. The quality of the image is very dependent on the patient remaining still, since movement causes severe loss of image (movement *artifact). The technique can also be used in nuclear medicine using two different tracers to look for parathyroid gland tumours.... digital subtraction
the rapid acquisition and manipulation of ultrasound information from a scanning probe by electronic circuits to enable images to be produced on TV screens almost instantaneously. The operator can place the scanning probe accurately on the region of interest in order to observe its structure and appreciate moving structures within it (see Doppler ultrasound). Using similar techniques, the instantaneous display of other imaging modalities, such as *computerized tomography scanning and *magnetic resonance imaging, can now be achieved. Real-time imaging is useful in guiding *interventional radiology procedures, for example, allowing a needle to be guided accurately as it is passed into the body. It is also useful for observing dynamic physiological activity.... real-time imaging
a pale area surrounded by haemorrhage sometimes seen in the retina, with the aid of an *ophthalmoscope, in those who have bacterial endocarditis, septicaemia, or leukaemia. [M. Roth (1839–1915), Swiss physician]... roth spot
a technique to image the parathyroid glands. Technetium is taken up only by the thyroid gland, but thallium is taken up by both the thyroid and parathyroid glands. *Digital subtraction of the two isotopes leaves an image of the parathyroid glands alone. It is an accurate technique (90%) for the identification of adenomas of the parathyroid glands secreting excess hormone.... thallium-technetium isotope subtraction imaging
see macula.... yellow spot
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